Heater 1 reading 160 C when off

beej

I've reconfigured my settings for a different problem see post
https://forum.duet3d.com/topic/24741/duet-maestro-driver-expansion-underpowered?_=1629790395857
Now my hotend is reading 160 when off. I have a hermera e3d hotend with the duet maestro board.
Is there anything wrong with my settings?

; Heaters
M308 S0 P"bedtemp" Y"thermistor" T100000 B4138 R2200    ; configure sensor 0 as thermistor on pin bedtemp
M950 H0 C"bedheat" T0                              ; create bed heater output on bedheat and map it to sensor 0
M307 H0 A78.9 C265.2 D9.5 S1.00 V24.0 B0           ; disable bang-bang mode for the bed heater and set PWM limit
M140 H0                                            ; map heated bed to heater 0
M143 H0 S120                                       ; set temperature limit for heater 0 to 120C

M308 S1 P"e1temp" Y"thermistor" T100000 B4725 C7.060000e-8   ; configure sensor 1 as thermistor on pin e1temp
M950 H1 C"e1heat" T1                               ; create nozzle heater output on e1heat and map it to sensor 1
M307 H1 A497.8 C237.9 D5.9 S1.00 V23.9 B0 ; disable bang-bang mode for heater  and set PWM limit
M143 H1 S280

jay_s_uk

@beej said in Heater 1 reading 160 C when off:

M308 S1 P"e1temp" Y"thermistor" T100000 B4725 C7.060000e-8 ; configure sensor 1 as thermistor on pin e1temp

maybe the resistor isn't being correctly identified? try adding R2200 to this.

Phaedrux

That would be strange. Leaving the R value off should use the default for your board.

Can you confirm your firmware version with M115?

If you send M98 P"config.g" do you get any errors?

Can you send M308 S1 in the console and tell us what it reports?

Where are you seeing the 160c reading?

What do you mean by "off", was it previously heated?

beej

@jay_s_uk
I did have the R value on then took it off to test that theory no change.

beej

@phaedrux
8/24/2021, 11:43:31 AM m308 s1
Sensor 1 type Thermistor using pin e1temp, reading 159.0, last error: sensor not ready, T:100000.0 B:4725.0 C:7.06e-8 R:2200.0 L:0 H:0

8/24/2021, 11:43:21 AM m98 P"config.g"
HTTP is enabled on port 80
FTP is disabled
TELNET is disabled

8/24/2021, 11:43:00 AM m115
FIRMWARE_NAME: RepRapFirmware for Duet 2 Maestro FIRMWARE_VERSION: 3.3 ELECTRONICS: Duet Maestro 1.0 FIRMWARE_DATE: 2021-06-15 21:47:09

8/24/2021, 11:41:32 AM Connection established

What I mean by off is I turn by printer on after hours if not days of it not running and it'll start of at 160.
I've changed the B value up to 1000000, and that dropped it down to 29C.

Could the board connection be bad? How could do I switch it to use E0, the other heater?

beej

@beej DWC temp.PNG

Phaedrux

@beej said in Heater 1 reading 160 C when off:

Could the board connection be bad? How could do I switch it to use E0, the other heater?

Connect your thermistor to the other temp port. ie e0temp

Change your M308 to use that new pin

M308 S1 P"e0temp" Y"thermistor" T100000 B4725 C7.060000e-8

Phaedrux

Does your wiring run next to anything that might be generating interference?

A good test may be to remove the thermistor from the hotend and reconnect it to the board with a new, shorter piece of wire.

beej

@phaedrux
I've used an different thermistor and connected it directly to the board and I'm getting the same result.
I switched to the other port and same number

dc42

@beej please run M308 H1 and report the response.

When you said "What I mean by off is I turn by printer on after hours if not days of it not running and it'll start of at 160" do you mean that after a while the temperature reading drops to the correct value?

Phaedrux

@dc42 said in Heater 1 reading 160 C when off:

@beej please run M308 H1 and report the response.

Previously it reported this

8/24/2021, 11:43:31 AM m308 s1
Sensor 1 type Thermistor using pin e1temp, reading 159.0, last error: sensor not ready, T:100000.0 B:4725.0 C:7.06e-8 R:2200.0 L:0 H:0

beej

@dc42 the moment I power up the duet it shows 159/158 and stays at that reading

beej

I've dropped the T value to 1000 and that puts it around 23C.
But when I set the heat to 200 and turn the heater on the measured values drops. Same if T is 100000. The measure value starts dropping.
Did I somehow screwup the board when I replaced a pin, 1) VIN on E3 was shorted?

dc42

@beej said in Heater 1 reading 160 C when off:

I've dropped the T value to 1000 and that puts it around 23C.
But when I set the heat to 200 and turn the heater on the measured values drops. Same if T is 100000. The measure value starts dropping.
Did I somehow screwup the board when I replaced a pin, 1) VIN on E3 was shorted?

It sounds to me that your "thermistor" may actually be a PT1000.

beej

@dc42
lol, Yea that was the problem.
I don't remember buying a different sensor and all my backups have a thermistor setup. Must not have saved a backup before.